Optical devices such as retardation films or polarizing plates may be, for example, used to adjust characteristics of light in display devices, or used for various applications including windows or shades in buildings or automobiles.
Such optical devices include a film obtained by adsorbing and aligning a dichroic dye on a polymer film such as a poly(vinyl alcohol) (PVA) film, a film manufactured using a liquid crystal compound and a dichroic dye, a film endowed with optical anisotropy by means of elongation, or a film endowed with optical anisotropy using a liquid crystal compound, as known in the related art.